Tetraethyllead antiknock additive

Frank Howard was also instrumental in the process research for Midgley s tetraethyllead antiknock additive, which led to Exxon s 50% ownership with General Motors of the Ethyl Corporation. Charles A. Kraus, an MIT staff member just before World War I, was its developer, and it appears that Doc Lewis found him for Exxon. Another Lewis idea later resulted in Exxon s fluidized bed iron ore process, commercialized after World War II only in Venezuela by the Arthur F. McKee Company. Someday, such a process might be incorporated in integrated steel minimills. 

This metal becomes a pollutant when released into aqueous streams from metal treatment and recovery plants (e.g., lead-using battery manufacturers). In industrialized nations, until the 1970s, a major source of air pollution was lead emission from the tetraethyllead antiknock additives to gasoline this is. still a problem in many underdeveloped nations. Once ingested, lead readily forms complexes with enzymatic oxo groups in the organism, thus interfering with all the steps in haemo... 

The alloy method is used in the manufacture of tetramethyl- and tetraethyllead, antiknock additives to petrol (p. 100). Similarly bismuth aryls were first made by Michaelis in 1877 by the reaction of powdered bismuth-sodium alloy with aryl halides,... 

The best known example is the electrosynthesis of tetraethyllead (TEL) Pb(C2Hj)4, which has been in wide use as an antiknock additive of gasoline, and still is in a number of countries. This substance is readily produced by reaction of ethyl radicals with the lead electrode ... 

Gasoline containing tetraethyllead as an antiknock additive was first sold by General Motors Development Co. in Dayton, Ohio, in February, 1923. Ethyl Gasoline Corporation was formed to exploit the antiknock business by General Motors and Standard Oil in August of 1924. Commercial production of tetraethyllead was begun for them by... 

Metallic lead is soft, bluish white, highly malleable, and ductile. It is a poor conductor of heat and electricity and resistant to corrosion. A protective film of basic carbonate is formed on the surface of lead exposed to moist air. Lead reacts with water in the presence of air to form lead hydroxide. Inorganic Pb(II) compounds are mainly insoluble or slightly soluble in water. Exceptions are lead chlorate, perchlorate, nitrate, and acetate. Lead chloride is moderately soluble (9.9 g/liter at 20°C). The most important organolead compounds are tetramethyllead and tetraethyllead used as antiknock additives in fuel. Both are colorless liquids at room temperature with boiling points 110 and 200°C, respectively. Photolytically these degrade to RaPb , R2Pb , and Pb. The different chemical forms of lead have different toxicity, so that speciation information is important [1,2]. 

Some coordination compounds have found application in the treatment of disease for example, gold compounds are used in arthritis therapy and platinum compounds are used in the treatment of some cancers. One organometallic compound which has been produced on an enormous scale is tetraethyllead for addition to motor fuels to improve their antiknock properties. An increasing appreciation of the dangers posed to human health by lead compounds is now leading to the phasing out of leaded fuels. 

The contamination of the environment with lead is increased by industrialization and by emissions from cars running on leaded gasoline. Tetraethyllead [(C2H5)4Pb], an antiknocking additive used to increase the octane value of gasoline. 

Among the latest additives (1957) are methyl cyclopentadienyl manganese tricarbonyl of the Ethyl Corporation, and an organic boron compound of the Standard Oil Company of Ohio. The boron compound in small amounts (0.008—0.03 per cent) not only reduces combustion-zone deposits and surface ignition but also increases the effectiveness of tetraethyllead. Antiknock effects are greatest with leaded straight-run or A[Pg.38]

Ethyl Chloride. Previously a significant use for industrial ethanol was the synthesis of ethyl chloride [75-00-3] for use as an intermediate in producing tetraethyllead, an antiknock gasoline additive. Ethanol is converted to ethyl chloride by reaction with hydrochloric acid in the presence of aluminum or zinc chlorides. However, since about 1960, routes based on the direct addition of hydrochloric acid to ethylene or ethane have become more competitive (374,375). 

Considerable controversy exists as to the identity of the active antiknock species when tetraethyllead is used in the fuel. Egerton and coworkers (44-8) concluded that antiknock substance must be oxidized, molecularly dispersed, and capable of existence in several stages of oxidation. Chamberlain, Hoare, and Walsh (21), in a series of detailed and comprehensive studies, concluded that tetraethyllead acts as an inhibitor by virtue of forming lead oxide (PbO). A large amount of additional evidence has been cited supporting the metal oxide theory (57, 79, 99,128,138). 

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